Instant powerwall

wim

Member
Joined
Apr 6, 2017
Messages
556
Hello all,

If you do not have the patience (like me) to collect, clean and test many many many used laptop cells or having a hard time to find them (also like me), using new cells is a fast(er) way to build a powerwall.
Instant powerwallmay be a bit of aoverstatement, it is still very muchtime consuming to build thepacks and the inclosure, but forsurefaster then collecting and testing used cells,so respect for all those who put in the time and effort toinspire and guideother builders.
After somedoubt, i like to share my build.

Love to get your remarks to do things better and safer.



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it is all up and running now, next step will be adding a " fast charger " with 3 Elcon flatpack2 chargers, controlled by the bms and powerdwith my generator with heat recovery, for the darker winter day's, not sure it will work but love to do some tests.
Also like to distribute the DCbattery powerfor all of the LED lights true the house (with some 12v converters.)

Some of thespecs:

Cells: Panasonic ncr18650pf, 2900mAh
battery setup: 2 strings 14s90p,all the cells are in parralel so more of a 14s180p setup, with space to expand (with used laptop cells? ;) )
inverter: infinisolar (mpp) 48v 10kw 3phase.
bms: batrium.
solar: 18x300Wp

Greatings,
Wim
 
Awesome!

what the cubboard you are using? Is it fire proof etc?

I see you have the contact coming off the same side of the pack. You might see the cell at the front discharge more then the ones at the back because of this.
 
The-J-Man said:
Awesome!

what the cubboard you are using? Is it fire proof etc?

I see you have the contact coming off the same side of the pack. You might see the cell at the front discharge more then the ones at the back because of this.

Thanks for the comment J-Man, the cubboard is a old type of officecabinet, it is all steel and the sides and doors are double steel with a solid lock and seal... so a kind of fire proof, at least fire retarding...
The connections of the packs are on the same side (so the wiringis the same length) but the"busbar"connecting the packs with the cable is a solid 2.5cm by 0.5cm copper bar, nolosses there, at least i can notmessureany with my meter, the packs stays at the same voltageat all times.
 
Awesome job man! I like the battery design alot in terms of how easy it would be to swap out a pack and all.

Batrium BMS and that green machine. Same way as I went :)

Can you link the contactor you used for the battery?
 
wim said:
The-J-Man said:
Awesome!

what the cubboard you are using? Is it fire proof etc?

I see you have the contact coming off the same side of the pack. You might see the cell at the front discharge more then the ones at the back because of this.

Thanks for the comment J-Man, the cubboard is a old type of officecabinet, it is all steel and the sides and doors are double steel with a solid lock and seal... so a kind of fire proof, at least fire retarding...
The connections of the packs are on the same side (so the wiringis the same length) but the"busbar"connecting the packs with the cable is a solid 2.5cm by 0.5cm copper bar, nolosses there, at least i can notmessureany with my meter, the packs stays at the same voltageat all times.

Ah ok nice, im Looking for a cabinet like that, Bit smaller though.
From what Ive gathered here everyone is having the busbars on the pack come out either side (positive one way, negative the other way)to make sure the cells discharge evenly as there is less resistance for the cells at the front then the ones at the rear. This would lead to the cells closest to the front discharge more then the rear.
Maybe ive misunderstood something but everyone is building packs with busbars coming out either end :D
BTW, one of my packs will be built from those same cells :)
 
daromer said:
Awesome job man! I like the battery design alot in terms of how easy it would be to swap out a pack and all.

Batrium BMS and that green machine. Same way as I went :)

Can you link the contactor you used for the battery?

Thanks,

Yeh, that green machine... a beast, powering my house with no problems...(not very much efficient maybebut... works for me )
The contactor is a adjustable 300Afuse with shunt trip from ABB, now connected to the bms, found it on ebay for 60 Euro (used of course).

ABB SACE S5 S5N Circuit Breaker 300AMP 3Pole 600V WITH SHUNT TRIP

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The-J-Man said:
wim said:
The-J-Man said:
Awesome!

what the cubboard you are using? Is it fire proof etc?

I see you have the contact coming off the same side of the pack. You might see the cell at the front discharge more then the ones at the back because of this.

Thanks for the comment J-Man, the cubboard is a old type of officecabinet, it is all steel and the sides and doors are double steel with a solid lock and seal... so a kind of fire proof, at least fire retarding...
The connections of the packs are on the same side (so the wiringis the same length) but the"busbar"connecting the packs with the cable is a solid 2.5cm by 0.5cm copper bar, nolosses there, at least i can notmessureany with my meter, the packs stays at the same voltageat all times.

Ah ok nice, im Looking for a cabinet like that, Bit smaller though.
From what Ive gathered here everyone is having the busbars on the pack come out either side (positive one way, negative the other way)to make sure the cells discharge evenly as there is less resistance for the cells at the front then the ones at the rear. This would lead to the cells closest to the front discharge more then the rear.
Maybe ive misunderstood something but everyone is building packs with busbars coming out either end :D
BTW, one of my packs will be built from those same cells :)
No, i did misunderstood... :s
On the packs themselve, the connections are also on the same side, you are right it is not perfect... but the draw of the cells is not that high, they have time to equilize if there is a difference in voltage between the cells... it is all in the resistance of thebusbars.
 
Wim,
Am I right in understanding that this is a pure off-grid setup with a generator for backup power?
That sails past the need to get your setup approved for grid usage off course.

What kind of appliances are running off this setup?

Keep up the good work!

Also Wim
 
That was a good price on that one :) Its kind of the same as I have looked at. I need a slightly bigger unit though.
 
wimpie007 said:
Wim,
Am I right in understanding that this is a pure off-grid setup with a generator for backup power?
That sails past the need to get your setup approved for grid usage off course.

What kind of appliances are running off this setup?

Keep up the good work!

Also Wim
Hello Wim,
My setup is not feeding back into the grid, but i have the grid still as back-up for now, the generator is a test to see if it is possible (read practical) to be off grid, will see after a year or soof usage.
As you know, it is not cheap to have solar feeding back into the grid in Belgium.

I run all of my appliances whith my setup, like oven, washer-drier, coocingplates, heatpump, for now even my warm water system (has to change).


daromer said:
That was a good price on that one :) Its kind of the same as I have looked at. I need a slightly bigger unit though.

Why am i not surprisedyou need a biggerfuse :rolleyes: i have seen your video's of your rebuild... nice btw, love the doors.
 
:) Thanks. Yeah im happy with the rebuild. Since I have 17kW of solar on the roof i need to dimension the breaker to that as well :)
 
daromer said:
:) Thanks. Yeah im happy with the rebuild. Since I have 17kW of solar on the roof i need to dimension the breaker to that as well :)


Daniel, are you going to usebreakers with shunt trip in the solar panel lines ?
It might be a good idea, this way it is possible to make a sort of safety master swith.... i mean one switch, a big red push button or so,to trip the breaker for the solar panels + the breaker for the battery and maybe also shuting of the inverters. Even remotly or by a fire-detector... a fireman will be happy
withsucha switch.
 
I have no plan to use shunt trip system for the PV side. It will only exist on the battery side and thats actually to protect the battery itself in terms of issues based on what the BMS feel. The BMS can/will also shut down the inverters if needed based on that part and adding fire sensing or heat on top is not hard either. Just not done right now.

Whats needed here in my area in terms of insurance and protection is external switches for the grid part and that exist. I have one on the outside of the building and 1 further away on incomming grid. Then it need to exist switches on PV/Battery/Grid close to the inverter and that all exist based on whats needed in Sweden.

Automatic systems is nice to have but in case of fire on the inverter side the automatic trip/shunt may not work anyways and does therefore not give any extra safety unless i go the extra mile and pay for fire proof cabinets for the switches and thats a huge huge cost. Ie for the button to work the cables to that part can not be harmed bu the fire. And if the fire isnt at the inverter side they can just flip the switches :)


I have looked into shunt/trip switches for everything and i decided not to go that mile and only make sure Im compliant and also make sure the battery part have all switches and monitoring that is recommended. If im just going to add extra shunts to the PV + grid + load we talk about an extra 1000 EUR :/ And then the fire cabinets with install is atleast 1500-2000EUR extra last time i checked. Its cheaper to install external PV switch and just use existing external GRID/Load switch that is manual.

I rather give some extra time in making sure fire wont happen on electronics side. One simple thing is to make sure no dust will get into the inverters :)

Hope my answer is enough and that it shows that I have given it a thought :)
 
daromer said:
I have no plan to use shunt trip system for the PV side. It will only exist on the battery side and thats actually to protect the battery itself in terms of issues based on what the BMS feel. The BMS can/will also shut down the inverters if needed based on that part and adding fire sensing or heat on top is not hard either. Just not done right now.

Whats needed here in my area in terms of insurance and protection is external switches for the grid part and that exist. I have one on the outside of the building and 1 further away on incomming grid. Then it need to exist switches on PV/Battery/Grid close to the inverter and that all exist based on whats needed in Sweden.

Automatic systems is nice to have but in case of fire on the inverter side the automatic trip/shunt may not work anyways and does therefore not give any extra safety unless i go the extra mile and pay for fire proof cabinets for the switches and thats a huge huge cost. Ie for the button to work the cables to that part can not be harmed bu the fire. And if the fire isnt at the inverter side they can just flip the switches :)


I have looked into shunt/trip switches for everything and i decided not to go that mile and only make sure Im compliant and also make sure the battery part have all switches and monitoring that is recommended. If im just going to add extra shunts to the PV + grid + load we talk about an extra 1000 EUR :/ And then the fire cabinets with install is atleast 1500-2000EUR extra last time i checked. Its cheaper to install external PV switch and just use existing external GRID/Load switch that is manual.

I rather give some extra time in making sure fire wont happen on electronics side. One simple thing is to make sure no dust will get into the inverters :)

Hope my answer is enough and that it shows that I have given it a thought :)

You dohave a point there... in case of afire in the inverter or battery cabinet, the shunts might not work... so no failsafe... :) smarter to stay on the road of prevention. :exclamation:
 
Update,

I am adding some Eltek "smart chargers", three of them, good for 90 Amp charging. :)
I do have a small problem now, sure there was some explanation how toconnect them to the bmson the Batrium website, but it isgone now.?? :huh:

No problem to connect justone, but three on the same can bus? do i need to do something special or just connect them in paralel ?
A bit of help of one of the experts is appreciated.


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Thanks,
 
wim said:
Some of thespecs:

Cells: Panasonic ncr18650pf, 2900mAh
battery setup: 2 strings 90p14s,all the cells are in parralel so more of a 180p14s setup, with space to expand (with used laptop cells? ;) )
inverter: infinisolar (mpp) 48v 10kw 3phase.
bms: batrium.

So correct me if I'm wrong here, and it's entirely possible, happens regularly haha, if you were to have say 4 strings, 90p14s, like we know Peter does for example, and u simply expanded on what u currently have setup, it would basically be a 360p14s ??
I assume there would be no problems with this setup??, Basically expand at will, once you get your first 14 packs setup you could almost just add a pack at a time as u make them??. How would you go with the 4kw pip4048, parallel versions, if my assumption on how they work is correct, would you require a second bank of 14 packs setup seperatly from the first, (I assume u can't run 2 pips on the same bank of batteries) and then expand on both setups as desired??
Cause if this is the case, and I'm hoping it is, Ur design of parralling the packs like that solves a number of my problems I see arising from my plans.
 
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Yes, you can build your wall that way by doubling the packs. However, what you need to do is make sure all your packs are balanced with each other capacity wise when doing that, and you need to do the whole 14s at once when you add another batch.
In other words, if you have 90p14s, and you built another 90p pack, you can't just parallel it with one of the 14's. You need to have a complete 14 packs to hook up. Or, at least, you should.
Otherwise, your charger is going to have a hard time keeping up with keeping everything balanced. It'll keep draining the other 13 packs to compensate for the one doubled up pack till it gets full. As the charger wants to do the whole thing at once and it'll be overcharging the other 13.
But if you put another 14 packs in parallel with the first batch, then everything is balanced across the board.

However, if you have the cells to build another 14 packs, then great! :) No worries


This is one reason why I don't care for this design. You can't add to it easily w/o needing a whole batch of packs. I prefer the 14sXp per pack, then parallel the packs together. But that does take more configuration for the balancers as each pack would need it's own balancer for each 14s in the pack.
 
Yes, at the end i (hope to) have 1 string of 360p14s, it not has to be, you coud add a string with just 60p or even less and change these packs over with bigger oneswhen you have the cells.
So a string of 20p14s combined with a string of 90p14s is no problem.
Just keep in mind the string of 14s needs to be build with packs that areat thesame or as close as possible the samecapacity, as always ( also with a setup as Pete's ) the only difference is my "cells" at the end are so big the bms (longmons) need to work harder.
To make the longmon's live easier, i have them sitting in aduct with a ventilator wich turns on when balancing, just to keep them cool. :cool:
Adding a pip is no problem, before or after expanding the battery capacity, the pip's need noting more than 48v, they dont care about capacity...



Korishan said:
Yes, you can build your wall that way by doubling the packs. However, what you need to do is make sure all your packs are balanced with each other capacity wise when doing that, and you need to do the whole 14s at once when you add another batch.
In other words, if you have 90p14s, and you built another 90p pack, you can't just parallel it with one of the 14's. You need to have a complete 14 packs to hook up. Or, at least, you should.
Otherwise, your charger is going to have a hard time keeping up with keeping everything balanced. It'll keep draining the other 13 packs to compensate for the one doubled up pack till it gets full. As the charger wants to do the whole thing at once and it'll be overcharging the other 13.
But if you put another 14 packs in parallel with the first batch, then everything is balanced across the board.

However, if you have the cells to build another 14 packs, then great! :) No worries


This is one reason why I don't care for this design. You can't add to it easily w/o needing a whole batch of packs. I prefer the 14sXp per pack, then parallel the packs together. But that does take more configuration for the balancers as each pack would need it's own balancer for each 14s in the pack.

True, buta string of 14s with just 10p (140 cells)is alsoposible to add ( or wathever "14sXp" you like ), it just needs to be a balanced string of 14 pacs... you always need those 14 packs to make 48V, adding just 1 packi aggree,will not work.
With a setup like Pete's the packsin a stringalso needs to bemore or less balanced.( correct me if i'm wrong )

It is all in the balance of things. ;)

Btw, always like to readyour posts, you know your stuff. :D
 
I'm starting to think we're all really trapeze artists instead of battery reclamation technicians. All this balancing can get a person pretty dizzy at the end of the day :p
 
Korishan said:
I'm starting to think we're all really trapeze artists instead of battery reclamation technicians. All this balancing can get a person pretty dizzy at the end of the day :p
Its a thin red line :)
 
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